package com.singleton.type1;

public class SingletonTest01 {
    public static void main(String[] args) {
        // 测试
        System.out.println("饿汉式静态常量");

        Singleton instance = Singleton.getInstance();
        Singleton instance2 = Singleton.getInstance();
        System.out.println(instance2 == instance);
        System.out.println("instance.hashCode=" + instance.hashCode());
        System.out.println("instance.hashCode=" + instance2.hashCode());
    }
}

// 恶汉式(静态变量)

class Singleton {
    // 1.构造器私有化，外部能new
    private Singleton() {

    }

    // 2.本类内部创建对象实例
    private final static Singleton instance = new Singleton();

    // 3.提供一个公有的静态方法，返回实例对象
    public static Singleton getInstance(){
        return instance;
    }
}
